PREDICTORS OF EARLY FAILURE OF FIXATION IN THE TREATMENT OF DISPLACEDSUBCAPITAL HIP-FRACTURES

Objective: To examine predictors of fixation failure in the treatment of displaced subcapital hip fractures. Design: Retrospective study. Me thods: All patients aged sixty-five years and older discharged from a large teaching hospital after treatment for displaced subcapital fract ure between April 1, 1989 and February 29, 1995 were identified (n = 3 44). Of these, 108 patients treated with internal fixation became the study group. Clinical information included demographics, implant, como rbidity, complications, mortality, surgeon's assessment of reduction, and need for revision. Pre operative x-ray information: Garden grade, Singh Index, Pauwel's angle, medial neck and femoral shaft cortex widt h, and displacement of fracture fragments. Postoperative: Quality of r eduction, a visible gap or step, evidence of union, fracture collapse, and failure. Results: The failure rate was 31 percent. The two most i mportant predictors were varus reduction and perceived difficulty in a chieving reduction. If the patient had a varus reduction or the surgeo n had difficulty achieving a satisfactory reduction, fixation was 4.3 times more likely to fail (p = 0.007). If the patient had a varus redu ction and reduction was difficult, fixation was 13.6 times more likely to fail (p = 0.04). Under this latter scenario, 75 percent of the fix ations failed. Conclusion: In a fracture of the neck of the femur, if difficulty is encountered in obtaining a closed reduction or there is residual varus angulation, the chance of subsequent fixation failure i s high. Hemiarthroplasty may be considered in these cases.